Background Growing use of imaging procedures in the United States has raised concerns about exposure to low-dose ionizing radiation in the general population. Methods We identified 952,420 non-elderly adults in 5 healthcare markets across the United States between July 1, 2005 and December 31, 2007. Utilization data were used to determine cumulative effective doses of radiation from imaging procedures in millisieverts (mSv) and to calculate population-based rates of “moderate” (>3 to 20 mSv per year), “high” (>20 to 50 mSv per year) and “very-high” (>50 mSv per year) doses. Results During the study period, 655,613 (68.8%) individuals underwent at least 1 imaging procedure associated with radiation exposure. The mean effective dose from imaging procedures was 2.4 mSv per person per year (std dev, 6.0 mSv); however, a wide distribution was noted with a median effective dose of 0.1 mSv per person per year (interquartile range, 0.0 to 1.7). Overall, the annual rate for moderate effective doses in the study population was 193.8 per 1000 enrollees, while high and very-high doses occurred at annual rates of 18.6 per 1000 enrollees and 1.9 per 1000 enrollees, respectively. In general, effective doses of radiation from imaging procedures increased with advancing age and were higher in women. Computed tomography and nuclear medicine scans accounted for 75.4% of the total effective dose and 81.8% occurred in non-hospitalized settings. Conclusions Imaging procedures are an important source of ionizing radiation in the United States and can lead to high radiation doses in patients.

Context Whether recent declines in ischemic heart disease and its risk factors have been accompanied by declines in heart failure (HF) hospitalization and mortality is not known. Objective To examine changes in HF hospitalization rate and 1-year mortality rate in the U.S., nationally and by state/territory. Design, Setting, and Participants 55,097,390 fee-for-service Medicare beneficiaries hospitalized between 1998 and 2008 in acute care hospitals in the U.S. and Puerto Rico admitted with a principal discharge diagnosis code for HF. Main Outcome Measures Changes in patient demographics and comorbidities, HF hospitalization rates, and 1-year mortality rates. Results The HF hospitalization rate adjusted for age, sex, and race declined from 2,845 per 100,000 person-years in 1998 to 2,007 per 100,000 person-years in 2008 (p<0.001), a relative decline of 29.5%. Age-adjusted HF-hospitalization rates declined over the study period for all race-sex categories. Black men had the lowest rate of decline (4,142 to 3,201 per 100,000 person-years) among all race-sex categories which persisted after adjusting for age (incidence rate ratio=0.81, 95% confidence interval [CI] 0.79 to 0.84). HF hospitalization rates declined significantly faster than the national mean in 16 states, and significantly slower in 3 states. Risk-adjusted 1-year mortality fell from 31.7% in 1999 to 29.6% in 2008 (p<0.001), a relative decline of 6.6%. 1-year mortality rates declined significantly in 4 states, but increased in 5 states. Conclusions The overall HF hospitalization rate declined substantially from 1998 to 2008, but at a lower rate for black men. The overall 1-year mortality rate declined slightly over the past decade, but remains high. Changes in HF hospitalization and 1-year mortality rates were uneven across states.

Background-Readmission soon after hospital discharge is an expensive and often preventable event for patients with heart failure. We present a model approved by the National Quality Forum for the purpose of public reporting of hospital-level readmission rates by the Centers for Medicare & Medicaid Services. Methods and Results-We developed a hierarchical logistic regression model to calculate hospital risk-standardized 30-day all-cause readmission rates for patients hospitalized with heart failure. The model was derived with the use of Medicare claims data for a 2004 cohort and validated with the use of claims and medical record data. The unadjusted readmission rate was 23.6%. The final model included 37 variables, had discrimination ranging from 15% observed 30-day readmission rate in the lowest predictive decile to 37% in the upper decile, and had a c statistic of 0.60. The 25th and 75th percentiles of the risk-standardized readmission rates across 4669 hospitals were 23.1% and 24.0%, with 5th and 95th percentiles of 22.2% and 25.1%, respectively. The odds of all-cause readmission for a hospital 1 standard deviation above average was 1.30 times that of a hospital 1 standard deviation below average. State-level adjusted readmission rates developed with the use of the claims model are similar to rates produced for the same cohort with the use of a medical record model (correlation, 0.97; median difference, 0.06 percentage points). Conclusions-This claims-based model of hospital risk-standardized readmission rates for heart failure patients produces estimates that may serve as surrogates for those derived from a medical record model. (Circ Cardiovasc Qual Outcomes.